Bill Galston has a piece in The New Republic listing the reasons why Barack Obama is going to have a tough time winning reelection in November. He’s right about most of them, but wrong about the one at the very top–he buys into the political science mythology that some presidential elections are referendums on the incumbent’s record and others are straight-ahead choices. I’ve seen some elections that are referendums on the President, but those have almost always been Congressional campaigns, like 2010 and 2006 or 1994. I don’t think I’ve ever seen a presidential election that was a pure referendum, and every presidential election I’ve covered involved a choice. There are good reasons for this.

The presidency is our most intimate office. The President lives in our homes for four years. The media spend considerable amounts of time, sometimes too much, telling us who these people are. And then in October we get to see two, occasionally three, men–only men, sadly, so far–on the stage and we decide which one we want to invite into our homes for the next four years. Barring a national disaster, issues are secondary–although an impression of how you might handle those issues is important. In 2008, for example, the causes of the financial collapse were abstruse, but Obama gave the impression that he understood what was happening and would handle it calmly. John McCain did not.

Some presidential elections have referendum aspects. In 1976, Jimmy Carter tried to make the election a referendum on Richard Nixon–and was in the process of failing at that, when Gerald Ford turned in a weak debate performance and saved the election for Carter. 1988 should have been a referendum on the Reagan presidency–Michael Dukakis surged to an early lead in the polls because people wanted a change, then crashed when he couldn’t answer a debate question about what he’d do if his wife were raped and murdered (We haven’t heard a debate like that in a while). I could go on.

But why, then, are congressional campaigns sometimes referendums? Because the candidates aren’t so well known–most people don’t know very much about their member of Congress–and the public tends to vote on its impression of how things are going in Washington. (In 1998, with the economy surging, the Democrats surprised most “experts” by winning seats in the midst of the Lewinsky scandal.)

In the end, though, presidential elections are about character, not policies. That is why Obama has a good chance to be reelected this year–people may disagree with or be disappointed by him, but they see him as smart and solid and decent. Mitt Romney may trump that in the debates this October, but for now he is perceived, especially by women, as inconstant and insensitive.